DETAILED ACTION
In Reply filed 6/24/2025, claims 1-4 and 6-10 are pending. Claims 1 and 7 are amended, claim 5 is canceled, and claims 1-10 are considered in current Office Action.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Maruyama (JP2012104573A; machine translation attached within previous Office Action) in view of Kondo (US20040061582A1), further in view of Chen (CN107146675A; machine translation attached within previous Office Action) and Kasada (US20200251135).
Regarding Claim 1, Maruyama discloses a method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate (Page 2, lines 47-51), comprising the following steps: S1. obtaining a phosphoric acid solution (Page 5, lines 54-60) made from phosphoric acid (Page 6, lines 7-12), and S2. placing a magnetic powder (Page 3 lines 28-38 and Page 5, lines 65-67) into a coating furnace (Page 6, lines 25-35 and 48-51), starting stirring, adding the phosphoric acid solution to the magnetic powder and continuing stirring (Page 5, lines 54-59).
Maruyama fails to explicitly state the S1. phosphoric acid solution was made by mixing phosphoric acid and deionized water uniformly in a ratio to obtain a phosphoric acid solution.
Kondo teaches an analogous method of forming coated iron-base magnetic powders [0009] wherein the phosphoric acid solution to make the primary insulation coating is made by any suitable way phosphoric acid solutions are made, such as mixing phosphoric acids in water uniformly in a ratio to obtain said phosphoric acid solution that can be used when contacting an iron-based magnetic powder [0055-0056]. Thus, one of ordinary skill in the art would have found it obvious to mix the phosphoric acid and deionized water uniformly in a ratio to obtain the benefit of a phosphoric acid solution that is usable when contacting an iron-based magnetic powder as taught by Kondo.
Maruyma further teaches S3. Adding a solution of nano-calcium ions (the type of calcium ion is not limited as long as it is derived from a calcium – for example it can be a calcium salt of inorganic bases, corresponding to a nano-calcium carbonate; Page 6, lines 4-13 and Page 2, line 40-45), continuing stirring (Page 5, line 59), and reacting to form a calcium phosphate (Ca(H2PO4)); Page 5, line 47) secondary coating layer on the surface of the magnetic powder particles (Page 6, line 15).
Maruyama fails to explicitly state in S.2 the adding a ratio of phosphoric acid to the magnetic powder of 10 wt%, and subjecting iron in the magnetic powder and phosphoric acid to a reaction to form a Fe(H2PO4)2 primary coating layer on a surface of magnetic powder particles, and in S.3 the nano-calcium carbonate is added in the amount of 0.1-2 wt% of the magnetic powder wherein the Ca(H2PO4)2 also acts as an adhesive in which unreacted nano-calcium carbonate is filled in the gap between the magnetic powder particles for further bonding and insulation.
Chen teaches an analogous method of manufacturing coated magnetic particles (Page 5, lines 2-7) wherein an insulating coating is made by two steps, the first coating made by adding 0.5-6 wt% of a strong acid with magnetic powder (powder being iron; Page 1, line 56-57), and water (corresponding to the phosphoric acid solution and magnetic powder) while heating and stirring so that the water evaporates (Page 5, lines 1-7), thereby forming a magnetic powder with greater DC bias characteristics (Page 2, lines 36-42). Chen further teaches the second step of making the secondary coating by adding nano-calcium carbonate in not more than 3% of the magnetic powder (Page 4, lines 1-7 and Page 2, lines 8-10), encompassing the instantly claimed range of 0.1-2%, thereby forming a magnetic powder with greater DC bias characteristics (Page 2, lines 36-42). The amount of nano-calcium carbonate added to the magnetic powder being no more than 3%, overlapping and encompassing the claimed ranges, would have been obvious to one of ordinary skill in the art at the time of invention so that the optimal amount of nano-calcium is added in order to obtain the benefit of a magnetic powder with greater DC bias characteristics. Further, while Maruyama teaches that said powder coating compositions comprise the phosphoric acid and nano-calcium carbonate, the reference does not explicitly disclose specific amounts of said components, specifically: a ratio of nano-calcium carbonate in the amount of 0.1-2 wt% of the magnetic powder. However, the routine experimental modification of Maruyama done in order to ascertain optimum properties of disclosed magnetic particle coating fails to render applicant's claims patentable in the absence of unexpected results. See In re Aller, 105 USPQ 233 and MPEP 2144.05. At the time of the invention a person having ordinary skill in the art would have found it obvious to optimize the amounts of nano-calcium carbonate and magnetic powder in the magnetic powder core and would have been motivated to do so in order to balance such properties as increased insulation, enhanced adhesion/bonding (Maruyama; Page 2, lines 15-21 and 40-45; Kondo [0037-0038]), and greater DC bias characteristics (Chen; Page 2, lines 36-42). Further, it is known that calcium carbonate acts as a binder/adhesive and insulator (Chen Page 7, lines 2-7), and further that the Ca(H2PO4)2 coating allows for increased coverage on the surface of the metal powder, increased insulation, and firmer bonding (Maruyama; Page 2, lines 15-21 and 40-45). Thus, when forming the Ca(H2PO4) layer through a reaction with nano-calcium carbonate and phosphoric acid, one of ordinary skill in the art would find it obvious that the Ca(H2PO4)2 also acts as an adhesive/binder in which unreacted nano-calcium carbonate of modified Maruyama is filled in the gap between the magnetic powder particles for further bonding and insulation as taught by Maruyama and Chen. Further, as discussed in MPEP 2143.A a person of ordinary skill would have found it obvious to combine prior art elements according to known methods to yield predictable results. In this case, one of ordinary skill in the art would have found it obvious reacting the nano-calcium carbonate and phosphoric acid would have yielded nothing more than the predicable result of forming Ca(H2PO4)2 which acts as an adhesive in which unreacted nano-calcium carbonate is filled in the gap between the magnetic powder particles for further bonding and insulation due to the enhanced binding and insulating effects of the material.
Maruyama in view of Chen fails to teach a ratio of phosphoric acid t the magnetic powder of 10 wt%.
However, Kasada teaches adding the phosphoric acid solution ([0265], binding agent) to the magnetic powder ([0265], ferromagnetic powder) with a ratio of phosphoric acid to the magnetic powder of 10 wt% ([0265], preferably 1.0 to 20.0 parts by mass with respect to 100.0 parts by mass of the ferromagnetic powder).
Maruyama and Kasada are considered to be analogous to the claimed invention because they are in the same field of magnetic powder coating. It would have been obvious to one with ordinary skill in the art before the effective filing date to modify the ratio of phosphoric acid to the magnetic powder in Maruyama to incorporate a ratio of 10wt% as taught by Kasada as described above, because the preferred ratio ensure the magnetic layer surface has a high strength and is difficult to be scarped (Kasada, [0203]).
Lastly, Kondo teaches that when the coating step in which a phosphoric acid solution is contacted with an iron-based magnetic powder, this forms an iron phosphate coating, thus forming a Fe(H2PO4)2 primary coating layer on the surface of the magnetic powder particles [0055]. As taught by Kondo, it would be obvious to one of ordinary skill in the art when subjecting iron in the magnetic powder and phosphoric acid this would result in a reaction to form a Fe(H2PO4)2 primary coating layer on a surface of the magnetic powder particles. As discussed in MPEP 2143.A a person of ordinary skill would have found it obvious to combine prior art elements according to known methods to yield predictable results. In this case, one of ordinary skill in the art would find it obvious that subjecting iron in the magnetic powder and phosphoric acid would result in a reaction to form a Fe(H2PO4)2 primary coating layer on a surface of magnetic powder particles as taught by Kondo forming the primary insulation layer.
Maruyama further teaches S4. the reaction temperature at the time of coating the surface of the metal powder, thus while stirring, is not limited but the reaction can be promoted by increasing the temperature and the time required for coating can be shortened, such as a temperature that is 70°C or more (Page 6, lines 48-51), to form a pretreated magnetic powder (i.e., the magnetic core powder before it is treated to form into the powder magnetic core; Page 7, lines 10-23). Maruyama fails to explicitly state this heating the coating furnace to a temperature of 120-130 °C, and continuing stirring until the resulting reactant is dry to obtain a pretreated magnetic powder.
Kondo teaches when forming the coating layer, the Fe(H2PO4)2 mixture was dried at 120°C in drying furnace to evaporate the solvent/water to obtain the pretreated magnetic core [0056 and 0096]. Thus, one of ordinary skill in the art would set the coating furnace temperature to the temperature, such as 120°C to evaporate the water from the mixture to obtain a pretreated magnetic powder than can be used in compression molding as taught by Kondo. While Maruyama does not explicitly disclose the heating the coating furnace to this specific 120-130 °C reaction temperature, the change in the reaction temperature of the heating element (“coating furnace”) is not considered to confer patentability to the claims. Maruyama teaches that it was known in the art at the time of the invention that increasing temperature will decrease the time required for coating (Page 6, lines 48-51) wherein Kondo teaches this temperature is set to evaporate the solvent from the mixture to obtain the coated powder. Therefore, the time of formation of the pretreated magnetic powder is a variable that can be modified, among others, by varying the temperature of said heater. For that reason, the heater temperature would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the heating temperature cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the heater temperature of Maruyama to obtain the desired reaction temperature and dryness of the pretreated magnetic powder (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Maruyama further discloses S5. adding zinc stearate as a lubricant to the pretreated magnetic powder, and mixing uniformly (Page 7, lines 20-23 and 37-38); S6. subjecting the uniformly mixed magnetic powder to a compression molding to obtain a compact (Page 7, lines 25-29); and S7. subjecting the compact to an annealing to obtain a secondary coated magnetic powder core with nano-calcium carbonate (Page 7, lines 56-60).
Maruyama teaches that it was known in the art at the time of the invention that controlling the amount of lubricant in order to form the dust core (Page 7, line 17-23). Therefore, forming the dust core can be achieved by mixing a lubricant with the magnetic core powder as necessary, press-molding and annealing the lubricant. Maruyama fails to explicitly state the lubricant being added in an amount of 0.3-0.4% of the weight of the pretreated magnetic powder.
Kondo also teaches the amount of lubricant ([0058] zinc stearate is a preferred lubricant) being added in an amount of 0.1 to 5% by mass ([0062]).
It would have been obvious to one with ordinary skill in the art before the effective filing date to modify the amount of lubricant in Maruyama to incorporate an amount of 0.3-0.4% by mass as taught by Kondo, in order to achieve uniform lubricant film (Kondo, [0062]).
Maruyama also fails to teach the compact is annular in shape. However, Kondo teaches the compact formed by magnetic powder ([0111] powder formed cores) is annular in shape ([0112] ring shaped cores). It would have been obvious to one with ordinary skill in the art before the effective filing date to modify the magnetic core in Maruyama to incorporate magnetic core cylinder with ring shape as taught by Kondo, in order to assess the magnetic characteristics (Kondo, [0117]).
Maruyama further discloses the magnetic powder mixture comprising pure Fe, FeSiAl or FeNi (thus meeting the claim limitation of one or more alloy powders selected from the group consisting of FeSiAl, FeSiNi, FeNi, FeNiMo, and FeSiCr; Page 3 lines 28-37).
Regarding Claim 2, modified Maruyama teaches a method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, but Maruyama fails to disclose the ratio of the phosphoric acid to the deionized water in step S1 is in the range of 1 : (1-10). Kondo teaches the ratio of phosphoric acid to the deionized water in step S1 is in the range of 0.01 10% by mass [0056]. While Maruyama teaches the phosphoric acid and phosphoric acid solution, the reference does not explicitly disclose specific amounts of the phosphoric acid within the solution, specifically: the ratio of the phosphoric acid to the deionized water in step S1 is in the range of 1 : (1-10). However, the routine experimental modification of Maruyama done in order to ascertain optimum properties of disclosed magnetic particle coating fails to render applicant's claims patentable in the absence of unexpected results. See In re Aller, 105 USPQ 233 and MPEP 2144.05. At the time of the invention a person having ordinary skill in the art would have found it obvious to optimize the amounts of phosphoric acid within the solution, and thus the ratio of phosphoric acid to the deionized water as taught by modified Maruyama and would have been motivated to do so in order to balance such properties as correct dilution/concentration of phosphoric acid within a phosphoric acid solution so that is can be usable when contacting an iron-based magnetic powder [0055-0056] thus allowing the coating reaction to occur with the increased insulation, enhanced adhesion/bonding (Maruyama; Page 2, lines 15-21 and 40-45; Kondo [0037-0038]) as taught by the references.
Regarding Claim 3, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein Maruyama further discloses the nano-calcium carbonate has a particle size of not more than 100 nm (Page 2, lines 40-45 and Page 3, lines 23-26).
Regarding Claim 4, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein the magnetic powder has an average particle size of 10-200 µm (Page 4, lines 10-19,58-60).
Regarding Claim 5, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein in step S5, the lubricant added is added in an amount of 1.0% of the weight of the pretreated magnetic powder, thus meeting the claimed amount (Page 7, lines 17-23; Page 8, lines 54-55)
Regarding Claim 6, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein Maruyama further discloses the stirring time when coating the surface of the metal powder with calcium phosphates varies depending on the concentration of the aqueous solution containing the calcium ions and the aqueous solution containing the phosphate ions (Page 6, lines 53-60). Maruyama further discloses if the mixing/reaction time becomes longer than necessary, and depending on the selected material, it becomes difficult to coat the metal powder without unevenness. Moreover, when reaction time is short, for example, about 1 to 10 minutes, the production generation of the target calcium phosphate is inadequate on the metal powder surface, and a yield fall and lack of insulation (specific resistance) are caused (Page 6, line 59 – page 7, line 3). As the stirring time after adding phosphoric acid and the stirring time after adding nano-calcium carbonate is a is a variable that can be modified by adjusting said reaction time of the coating reaction, with said production generation increasing as the stirring time of the steps are increased/decreased is increased, as evidenced by Maruyama the precise stirring time of the steps would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed stirring time after adding phosphoric acid and after adding nano-calcium carbonate cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the stirring times of Maruyama to obtain desired degree of insulation, production generation, and uniformity of the coating (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Regarding Claim 7, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein in step S6, the compression molding is carried out at a pressure of 1500-2300 MPa (Page 7, lines 40-48).
Regarding Claim 8, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 1, wherein the annealing is performed at a temperature of 600-800 °C for 30-90 min under an atmosphere of nitrogen or hydrogen (Page 8, lines 55-60).
Regarding Claim 9, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 4, wherein Maruyama discloses aluminum is added to the FeSi for the purpose of improving magnetic properties (Page 3, lines 36-38). Maruyama fails to explicitly state that the FeSiAl has a chemical composition of 87.8 % of iron, 6.8 % of silicon and 5.4 % of aluminum. However, Kondo teaches that when silicon and nickel are added to the iron powder that they both must be 7% by mass or less to obtain the benefit of high magnetic flux density, low coercive force, and a powder that is not too hard that it is difficult to improve the density of the powder magnetic core [0043]. Thus, prior to the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the FeSiAl composition of Maruyama to be 87.5% iron, 6.8% silicon, and 5.4% aluminum to obtain the benefit of high magnetic flux density, low coercive force, and a powder that is not too hard that it is difficult to improve the density of the powder magnetic core as taught by Kondo. Further, in claim 4 the rejection does not rely on FeSiAl; thus, all of the limitations of this claim are met.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Maruyama (JP2012104573A) in view of Kondo (US20040061582A1), Chen (CN107146675A), and Kasada (US20200251135), as applied to Claim 4 above, further in view of Maeda (US20100193726A1).
Regarding Claim 10, modified Maruyama teaches the method for secondary coating of a magnetic powder core using phosphoric acid and nano-calcium carbonate of claim 4, wherein Maruyama discloses the magnetic powder can contain iron and nickel wherein the ratio is not limited (Page 3, lines 43-44) and where Nickle is added for the purpose of improving magnetic properties (Page 3, lines 36-38) . Maryuama fails to explicitly state FeNi has a chemical composition of 54.5 % of iron and 45.5 % of nickel. Maeda teaches an analogous method of producing an iron-based dust core (Abstract) wherein the magnetic powder can be FeNi wherein the iron content is preferably 50% by mass or more (thus, 54.5% iron), thereby the remaining amount will be nickel (thus, 45.5% nickel) [0055].
While Maruyama fails to explicitly state FeNi has a chemical composition of 54.5 % of iron and 45.5 % of nickel, the routine experimental modification of Maruyama done in order to ascertain optimum properties of disclosed powder core fails to render applicant's claims patentable in the absence of unexpected results. See In re Aller, 105 USPQ 233 and MPEP 2144.05. At the time of the invention a person having ordinary skill in the art would have found it obvious to optimize the amounts of iron and nickel in the magnetic powder of Maruyama and would have been motivated to do so in order to balance such properties as improving the magnetic properties of the powder (Page 3, lines 36-38). Further, as taught by Maeda, this specific amount is known in the art and therefor would be an obvious amount. Further, in claims 1 and 4 the rejection does not rely on FeNi; thus, all of the limitations of this claim are met.
Response to Arguments
Applicant's arguments filed 6/24/2025 have been fully considered but they are not persuasive.
Regarding claim 1, applicant argues that Maruyama fails to teach the lubricant being added is in an amount of 0.3-0.4% of the weight of the pretreated magnetic powder.
However, Kondo also teaches the amount of lubricant ([0058] zinc stearate is a preferred lubricant) being added in an amount of 0.1 to 5% by mass ([0062]). It would have been obvious to one with ordinary skill in the art before the effective filing date to modify the amount of lubricant in Maruyama to incorporate an amount of 0.3-0.4% by mass as taught by Kondo, in order to achieve uniform lubricant film (Kondo, [0062]).
Applicant further argues that Maruyama in view of Kondo fails to teach the iron core was formed in annular shape.
The examiner respectfully disagrees. In addition to teaching the iron core was formed as a cylinder shape with annular grooves, Kondo also teaches forming core cylinder with ring shape ([0112]). It would have been obvious to one with ordinary skill in the art before the effective filing date to modify the magnetic core in Maruyama to incorporate magnetic core cylinder with ring shape as taught by Kondo, in order to assess the magnetic characteristics (Kondo, [0117]).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TIFFANY YU HUANG whose telephone number is (571)272-2643. The examiner can normally be reached 9:00AM - 5:00 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Susan Leong can be reached at (571) 270-1487. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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TIFFANY YU. HUANG
Examiner
Art Unit 1754
/SUSAN D LEONG/Supervisory Patent Examiner, Art Unit 1754